# Got my first laser and it will not cut

**URL:** <https://forum.lightburnsoftware.com/t/got-my-first-laser-and-it-will-not-cut/192760>\
**Category:** Community Laser Talk\
**Tags:** omtech\
**Created:** [September 25, 2026, 8:53pm UTC](https://forum.lightburnsoftware.com/t/got-my-first-laser-and-it-will-not-cut/192760 "2026-09-25T20:53:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![webweaver](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/webweaver/32/125343_2.png) [@webweaver](https://forum.lightburnsoftware.com/u/webweaver)\
**Post date:** [September 25, 2026, 8:53pm UTC](https://forum.lightburnsoftware.com/t/got-my-first-laser-and-it-will-not-cut/192760/1 "2026-09-25T20:53:57Z")

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So I got an Omtech k40+. I did the initial set up. Then got Lightburn installed and communicating with the laser. I then tested the alignment with some paper. I hit the test button and everything seemed fine. I then went to Lightburn and tried to create a test cut. I turned on the cut selected graphics option. Then hit start. The laser moves but does not actually fire the laser. The laser current display says.

Laser signal on but it reads 00mA.

If I press and hold the test button it will fire the laser. But if I do not press the test button it will not fire the laser. Is there some kind of setting I need to turn on to tell lightburn to tell my laser to fire? I have been doing research and im finding all sorts of things from wire harnesses not being wired correctly. To the water pump sensor failing.  
I need some help with this since I am on a time crunch and was planning on using this for a project.

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**Author:** ![Gneaton](https://forum.lightburnsoftware.com/letter_avatar_proxy/v4/letter/g/a698b9/32.png) [@Gneaton](https://forum.lightburnsoftware.com/u/Gneaton)\
**Post date:** [September 25, 2026, 11:24pm UTC](https://forum.lightburnsoftware.com/t/got-my-first-laser-and-it-will-not-cut/192760/2 "2026-09-25T23:24:19Z")

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If the laser fires when you hold the test button, the laser itself is working. What settings in Lightburn have you got for your cut? I’m not familiar with your laser, but most CO2 lasers will not fire if the setting is under a certain percentage - on mine it is 12%. To actually cut (depending on material and thickness) I typically use 40% and 5mm/s with a 100w CO2 laser for 6mm acrylic.

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**Author:** ![MikeyH](https://forum.lightburnsoftware.com/letter_avatar_proxy/v4/letter/m/43a26b/32.png) [@MikeyH](https://forum.lightburnsoftware.com/u/MikeyH)\
**Post date:** [September 26, 2026, 1:02am UTC](https://forum.lightburnsoftware.com/t/got-my-first-laser-and-it-will-not-cut/192760/3 "2026-09-26T01:02:03Z")

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> [@webweaver](#):
>
> To the water pump sensor failing

This could happen if you have air in the lines.

The K40+ uses a GRBL controller, so check the Console window for any possible error messages.

Enter **$$** in the Console window and make sure the **$30** parameter matches the **S-value Max** in the Device Settings window, Basic Settings tab. It is normally **1000**.

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**Author:** ![Dominic](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/dominic/32/25713_2.png) [@Dominic](https://forum.lightburnsoftware.com/u/Dominic)\
**Post date:** [September 26, 2026, 6:29am UTC](https://forum.lightburnsoftware.com/t/got-my-first-laser-and-it-will-not-cut/192760/4 "2026-09-26T06:29:45Z")

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Hi @webweaver

Can you check the machine’s safety interlocks — particularly the **water protection** and **lid/cover protection**?

Make sure coolant is flowing normally, the lid is fully closed, and the debris tray is pushed fully home.

OMTech has a troubleshooting guide for this exact symptom here:  
[https://help.omtechlaser.com/hc/en-us/articles/33069770421017-Software-failure-to-fire-the-laser-Test-button-works](https://help.omtechlaser.com/hc/en-us/articles/33069770421017-Software-failure-to-fire-the-laser-Test-button-works)